From the Heart of the World: The Elder Brothers' Warning - Kogi Message to Humanity

They've shunned modern man their entire history and only recently made contact with one journalist to give him their msg to humanity before returning to tribal solitude forever more in the amazon. Their medicine people are placed in a dark cave at birth and have never seen daylight or the real world till they are 18 or something crazy like that....The sheer knowledge they've accumulated due to that, amongst other things is insane.